Polymer treating method and apparatus

ABSTRACT

A polymer treating method has the steps of: reacting a polymer compound with a reaction agent in a reaction vessel to generate a polymer treatment product; discharging the polymer treatment product containing the reaction agent from the reaction vessel; depressurizing the polymer treatment product; introducing the polymer treatment product into a degassing extruder; separating the reaction agent from the polymer treatment product through a vent box that is connected to upstream of the degassing extruder and that has a volume of equal to or more than that of the reaction vessel; and extruding the polymer treatment product from the degassing extruder.

The present application is a division of U.S. application Ser. No.10/958,730, filed Oct. 6, 2004 now U.S. Pat. No. 7,186,794, which isbased on Japanese patent application No. 2004-149230, the entirecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a polymer treating method and a polymertreating apparatus that a polymer is processed into thermoplastic resinor wax by denaturalization or decomposition, or by cutting thecross-link point or molecular chain of cross-linked polymer, and moreparticularly to a polymer treating method and a polymer treatingapparatus that a polymer is reacted with a reaction agent insupercritical state by using an extruder.

2. Description of the Related Art

In recent years, as environment problems become important, the cost indisposal of wastage tends to increase. Regeneration or recycle ofpolymer is also desired. In this trend, the material recycle ofthermoplastic resin is developed since it is possible to mold thethermoplastic resin again by using the fluidization property obtained byheating.

However, a thermosetting resin, a cross-linked polymer, rubber etc. aredifficult to apply to the material recycling since the fluidizationproperty thereof cannot be obtained even by heating due to the molecularthree-dimensional network. Therefore, although the thermal recyclingthereof is somewhat done, they are mostly discarded as landfill wasteetc.

A technique is researched that realizes the material recycle ofthermosetting resin or cross-linked polymer. For example, proposed are amethod of processing a polymer into thermoplastic resin by deforming themolecular three-dimensional network structure to recycle it, and amethod of making low-molecular substance (wax substance) by cutting theprincipal chain of a polymer to reuse it as an additive.

In order to put such a method into practical use, a means for treatingthe polymer continuously is required. Extruders are suitable for thatpurpose. Heat and pressure conditions required in processing a stablethermosetting resin or cross-linked polymer into thermoplastic resin bydeforming the molecular three-dimensional network structure can beeasily satisfied by the extruders. Those in making a wax substance canbe easily satisfied thereby as well. Also, in making the thermoplasticresin, a thermosetting resin or other agent can be easily added to thethermosetting resin or cross-linked polymer by using the extruder.

Japanese patent application laid-open No. 2001-253967 (prior art 1)discloses a method that cross-linked polyethylene and water are suppliedinto an extruder, and are processed into a thermoplastic material byextruding under conditions to make water to be supercritical orsemi-critical in the extruder, i.e., at a temperature of 200 to 1000° C.and a pressure of 2 to 100 MPa.

Japanese patent application laid-open No. 2002-249618 (prior art 2)discloses a method that a cross-linked polymer is introduced with ahigh-temperature and pressure fluid into a reaction vessel to generate areacted substance, the reacted substance is introduced into a separatorto be separated from the high-temperature fluid, and the reactedsubstance is extruded by the extruder.

In prior art 1, water serves as a reaction agent to process thethermosetting resin or cross-linked polymer into the thermoplasticmaterial under the chemical reaction. However, prior art 1 does notdisclose an effective means for separating the thermoplastic materialafter mixing the reaction agent with the thermosetting resin.

In prior art 2, a separation bath is used to separate the polymer fromgas after mixing the reaction agent with the thermosetting resin.However, since the extruder of prior art 2 has to be disposed spatially,the manufacturing cost of apparatus increases. Further, if the polymergenerated sticks to the wall of separation bath, it is difficult tosupply the polymer into the degassing extruder.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a polymer treating methodthat a polymer treatment product discharged from the reaction vessel canbe stably supplied to the degassing extruder while preventing pressurefluctuation caused by the abrupt expansion of reaction agent.

It is a further object of the invention to provide a polymer treatingapparatus that a polymer treatment product discharged from the reactionvessel can be stably supplied to the degassing extruder while preventingpressure fluctuation caused by the abrupt expansion of reaction agent.

According to the first aspect of the invention, a polymer treatingmethod comprises the steps of:

reacting a polymer compound with a reaction agent in a reaction vesselto generate a polymer treatment product;

discharging the polymer treatment product containing the reaction agentfrom the reaction vessel;

depressurizing the polymer treatment product;

introducing the polymer treatment product into a degassing extruder;

separating the reaction agent from the polymer treatment product througha vent box that is connected to upstream of the degassing extruder andthat has a volume of equal to or more than that of the reaction vessel;and

extruding the polymer treatment product from the degassing extruder.

The above polymer treating method may employ the next modifications:

(i) The degassing extruder may be a double-shaft extruder.

(ii) The degassing extruder may comprise a vent disposed on thedischarge side thereof so as to remove the reaction agent remaining inthe polymer treatment product.

(iii) The reaction vessel may be a distribution type reaction vesselthat is connected to a polymer material supplying extruder at previousstage.

(iv) The depressurizing step may be conducted by a decompression device,and the extruding step may comprise a step of extruding the polymertreatment product from the degassing extruder while molding the polymertreatment product.

(v) The separating step may comprise a step of separating an impurityfrom the separated reaction agent and then storing the separatedreaction agent so as to recycle it.

(vi) The polymer treating method may further comprise the steps of:

cooling the extruded polymer treatment product; and

cutting the cooled polymer treatment product.

(vii) The reacting step may comprise any one of denaturalization,decomposition and cross-link cutting reactions applied to the polymercompound.

(viii) The polymer compound may be a cross-linked polymer, and thereaction agent may be alcohols or a mixture containing alcohols.

(ix) The polymer compound may be previously pelletized prior toapplication of the polymer treating method.

According to the second aspect of the invention, a polymer treatingapparatus for reacting a polymer compound with a reaction agent in areaction vessel to generate a polymer treatment product comprises:

a decompression device that decompresses the polymer treatment productcontaining the reaction agent discharged from the reaction vessel;

a degassing extruder into which the polymer treatment product dischargedfrom the decompression device is introduced and which extrudes thepolymer treatment product; and

a vent box that is connected to upstream of the degassing extruder andthat has a volume of equal to or more than that of the reaction vessel,the vent box serving to separate the reaction agent from the polymertreatment product.

The above polymer treating apparatus may employ the next modifications:

(i) The polymer treating apparatus may further comprise:

an impurity separation device that is connected to the vent box so as toseparate an impurity from the separated reaction agent; and

a pressure adjusting device that is disposed between the vent box andthe impurity separation device so as to keep constant the inner pressureof the vent box,

wherein the vent box comprises a heating device that is disposed on theperiphery of the vent box so as to heat the vent box.

(ii) The vent box may comprise a relief valve to prevent from the riseof the pressure limit for the vent box.

(iii) The heating device may comprise an electric heater that isdisposed on the periphery of storing portion for the polymer treatmentproduct of the vent box.

(iv) The heating device may comprise a jacket for circulation of heatingmedium that is disposed on the periphery of storing portion for thepolymer treatment product of the vent box, and a heating mediumcirculation unit that supplies the heating medium to the jacket.

(v) The impurity separation device may comprise a storing tank thatstores the separated reaction agent, and the stored reaction agent maybe supplied to the reaction vessel with the polymer compound.

(vi) The impurity separation device may comprise a filter that canseparate the reaction agent from the powder from the degassing extruder.

(vii) The polymer treating apparatus may further comprise:

a cooling device that cools the polymer treatment product extruded fromthe degassing extruder; and

a cutting device that cuts the cooled polymer treatment product.

(viii) The decompression device may comprise a discharge valve.

(ix) The decompression device may comprise a resistor body with multipleholes.

(x) The decompression device may comprise a resistor body with multipleholes and/or a flow rate adjusting valve.

Thus, in the invention, the degassing extruder is provided with the ventbox as vent back that has a volume of equal to or more than the reactorvessel. Thereby, the reaction agent can be stably separated from thepolymer treatment product. Therefore, the polymer treatment productdischarged from the reaction vessel can be stably supplied to thedegassing extruder while preventing pressure fluctuation caused by theabrupt expansion of reaction agent.

Even when resin containing a great amount of reaction agent isdischarged from the polymer material supplying extruder to the degassingextruder, due to the large volume of vent box, the inner pressure ofdegassing extruder can be sufficiently decompressed while preventing theblockage in exhaust port of the vent box. Thus, the vent box serves as abuffer to pressure fluctuation. Thereby, pressure fluctuation insubsequent portions can be also suppressed, and the polymer treatmentproduct can be subjected to the continuous and uniform molding.

It is more desirable that, in order to prevent the scattering ofreaction agent caused by excess pressure rise, the volume of vent box isabout Pv-times greater than that of the reactor vessel where the innerpressure of reactor vessel is Pv [MPa]. Thereby, even if gas in thereactor vessel is all flown into the vent box, the pressure of vent boxcan be kept lower than 1 MPa.

It is desirable that the vent box has the relief valve to keep thepressure of the vent box lower than 1 MPa.

In the invention, “polymer” means a synthetic polymer such ascross-linked polymers, plastics and rubbers, a natural polymer such aslignins, celluloses and proteins, and a mixture of synthetic polymer andnatural polymer. Further, it may contain materials other than polymersas a main component, like a shredder dust.

The method and apparatus of the invention are especially effective forthe case of using a cross-linked polymer as the polymer and alcohols ora mixture containing alcohols as the reaction agent. Also, they are veryeffective for a case that at a high pressure as supercritical state, thesuppression of pressure fluctuation as well as securing a sufficientreaction time is desired to facilitate the reaction with reaction agent.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments according to the invention will be explainedbelow referring to the drawings, wherein:

FIG. 1 is a flow diagram showing a cross-link cutting treatmentapparatus for cross-linked polyethylene in a preferred embodiment of theinvention;

FIG. 2 is a flow diagram showing a cross-link cutting treatmentapparatus for cross-linked polyethylene in another preferred embodimentof the invention;

FIG. 3 is a system diagram showing a vent box pressure adjustmentmechanism disposed at the subsequent stage of polymer material supplyingextruder 1 according to the invention; and

FIG. 4 is a flow diagram showing a cross-link cutting treatmentapparatus for cross-linked polyethylene as comparative example 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a flow diagram showing a cross-link cutting treatmentapparatus for cross-linked polyethylene in the preferred embodiment ofthe invention.

Referring to FIG. 1, cross-linked polyethylene being pelletized is putthrough a hopper 13 in a polymer material supplying extruder 1 (cylinderdiameter of 33 mm, L/D=50). On the other hand, ethanol as a reactionagent necessary for the reaction is supplied from a reaction agent tank18 through a valve 17 to the polymer material supplying extruder 1 whilebeing compressed by a reaction agent supplying pump 15 and heated by areaction agent heater 14. The supply position of reaction agent isdesirably located downstream of a position where cross-linkedpolyethylene is sufficiently densified in the polymer material supplyingextruder 1. Thereby, the reaction agent can be prevented from leakingtoward upstream due to evaporation thereof.

The polymer material supplying extruder 1 uses a double-shaft extruderthat has two screws 1 a to prevent the flowback of high-temperature andpressure reaction agent and to facilitate the mixing of reaction agent.In the reaction agent supplying pump 15, it is required that thereaction agent is compressed higher than internal pressure of polymermaterial supplying extruder 1. In the reaction agent heater 14, it isdesirable that the reaction agent is heated so as not to lower thetemperature of polymer being increased by the polymer material supplyingextruder 1. In the polymer material supplying extruder 1, thecross-linked polyethylene is mixed and agitated with the reaction agentby the screws 1 a. In this process, at least part of the polymermaterial supplying extruder 1 is controlled to satisfy the temperatureand pressure conditions that the reaction agent, ethanol is insupercritical state. Thereby, the cross-link cutting reaction betweencross-linked polyethylene and ethanol proceeds sufficiently to have agood polymer treatment product. In this embodiment, a distribution typereaction vessel 100 with a volume of 50 litters is connected to thepolymer material supplying extruder 1 so as to obtain a sufficientreaction time.

The mixture of: the polymer treatment product being plasticized fromcross-linked polyethylene by the polymer material supplying extruder 1and the distribution type reaction vessel 100; and the and the reactionagent, ethanol is stepwise depressurized by a decompression valve 11 (ordischarge valve) as a pressure reducing means, and then by a breakerplate 31, which is a resistor body with multiple holes for decompressionof the resin, attached to the decompression valve 11.

A degassing extruder 2 is further connected at the subsequent stage. Inthe degassing extruder 2, the polymer treatment product as viscousliquid is extruded by a screw 2 a in the extrusion direction of thedegassing extruder 2, and its gas component is flown into a vent box 8as vent back with a reduced pressure. Thus, the reaction agent isseparated from the polymer treatment product.

The vent box 8 is heated by a heater 10, an electric heater, for heatingthe vent box so as to be kept at a temperature that the polymertreatment product is fluidized.

Instead of using the heater 10, the vent box 8 may be heated by using,though not shown, a jacket for circulation of heating medium that isdisposed on the periphery of storing portion for the polymer treatmentproduct of the vent box 8, and a heating medium circulation unit thatsupplies the heating medium to the jacket.

The vent box 8 has a volume of 100 litters twice the volume ofdistribution type reaction vessel 100. Since the vent box 8 has a volumegreater than that of the distribution type reaction vessel 100, theinner pressure of vent box 8 can be reduced to ½ or lower than that ofthe distribution type reaction vessel 100 even if the resin and gas isextruded intermittently. The inner pressure of vent box 8 is keptslightly higher than atmospheric pressure and lower than that of thedistribution type reaction vessel 100. Therefore, the polymer treatmentproduct can be easily discharged from the vent box 8. In the vent box 8,light gas is separated to the top of vent box 8 and the polymertreatment product in melting state is retained to the bottom of vent box8. The polymer treatment product is moved, by its own weight, from ahole at the bottom to the degassing extruder 2, and then molded by a die3 at the discharge end of degassing extruder 2.

The degassing extruder 2 may be a single-shaft or double-shaft extruder.In this embodiment, the polymer treatment product is molded into afilamented strand 5 and is then cooled and hardened nearly at roomtemperature by a cooler 4. The strand 5 is cut into pellets 7 by astrand cutter 6. The degassing extruder 2 may be, as shown in FIG. 2,equipped with a vent 9 so as to perfectly remove the reaction agent fromthe resin.

On the other hand, the reaction agent, ethanol separated from thepolymer treatment product in the vent box 8 is depressurized toatmospheric pressure through a tank pressure adjusting valve 12, andthen transferred to an impurity separation tank 16. In the impurityseparation tank 16, impurities generated in the reaction process andmixed in the reaction agent, ethanol are separated using a difference ofboiling points. Ethanol is returned to the reaction agent tank 18, andthe impurities are drawn through a blower 19 into a combustor 20, wherethey are burned.

The apparatus thus composed is especially effective for a case that thepolymer treatment product has such a high viscosity as it does not flowbefore applying some force thereto. In prior arts 1 and 2 mentionedearlier, where the distribution type reaction vessel 100 is not used,the amount of processing per unit time must be limited if the polymermaterial supplying extruder 1 with a certain size is used since there isa limitation in elongating the cylinder of polymer material supplyingextruder 1. In contrast, when the distribution type reaction vessel 100is used, the amount of processing per unit time can be increased since anecessary reaction time can be arbitrarily secured by changing the sizeof distribution type reaction vessel 100. Such an apparatus is effectivefor a chemical reaction requiring a time more than 30 minutes, such as asilane cross-link cutting reaction between silane cross-linkedpolyethylene and alcohol.

When the polymer treatment product in melting state and the gaseousreaction agent are intermittently, not continuously, extruded throughthe decompression valve 11 from the polymer material supplying extruder1, the gas is blown out therefrom while involving the polymer treatmentproduct since it expands from compression state. Even in this case, thevent box 8 serves as a buffer against the pressure variation since ithas a sufficient volume. Thus, the pressure fluctuation can be preventedin the extrusion direction of resin. Therefore, the molding of resin canbe continued smoothly.

Further, since the polymer treatment product is sent from thedistribution type reaction vessel 100 through the piping system to thedegassing extruder 2, the problems in prior art 2 are not generated thatwhen the polymer treatment product sticks to the wall of separationbath, it is difficult to extrude or due to the high viscosity of polymertreatment product, the supply of resin to the degassing extruder 2discontinues. Thus, variation in the supply amount of resin can bereduced and the polymer treatment product can be supplied constantly.

When the vent box 8 is not used, the pressure fluctuation increases dueto expansion of gas. Since this affects directly the molding side, thesupply amount of material to the degassing extruder 2 is fluctuated orthe gaseous reaction agent and polymer treatment product is blown outfrom a vent.

However, in this embodiment, since the degassing extruder 2 is equippedwith the large vent box 8, even after the plasticization reactiongenerated at a high pressure, fluctuation in the supply amount ofmaterial to the degassing extruder 2 can be reduced and the mixed gascan be perfectly removed from the resin while kneading the mixture.Further, since it does not use the method of dropping, by its ownweight, the polymer treatment product in a degassing bath, the entireapparatus can be in planar arrangement and the cost of apparatus can belowered.

FIG. 3 is a system diagram showing a vent box pressure adjustmentmechanism disposed at the subsequent stage of polymer material supplyingextruder 1 according to the invention.

The mixture of polymer treatment product and reaction agent dischargedfrom the polymer material supplying extruder 1 in FIG. 1 isdepressurized to 1 to several tens of atm from the inner pressure ofpolymer material supplying extruder 1 by the decompression valve 11, andthen is supplied to the degassing extruder 2 where the gaseous reactionagent is separated from the viscous liquid polymer treatment product. Inthe depressurization by the decompression valve 11, the gaseous reactionagent component being compressed at a high pressure expands andsimultaneously is blown out inside the vent box 8. In this case, sincethe volume of vent box 8 is sufficiently greater than that of theblown-out gas, the fluctuation of pressure can be suppressed to someextent. However, the next mechanism allows further stabilization ofpressure.

The inner pressure of vent box 8 is measured by a pressure indicator 70with pressure signal generator, and the pressure signal measured istransferred through a signal transmission line 72 to a pressure controldevice 71. The pressure control device 71, according to the pressuresignal transferred, sends a valve open/close signal through the signaltransmission line 72 to the pressure adjusting valve 12. The pressureadjusting valve 12 is an air-actuation type valve and, according to thetransmitted signal, adjusts the opening of valve. The opening adjustmentof valve 12 is adjusted such that the inner pressure of vent box 8 iskept constant.

Alternatively, the pressure adjustment may be conducted by thecooperation between the decompression valve 11 and the pressureadjusting valve 12. In this case, adding to the pressure indicator 70with pressure signal generator, means for measuring a pressuredifference between forward and back of the decompression valve 11 isprovided, and both the former and the latter are controlled to haveconstant pressures. In controlling the pressure by using both thedecompression valve 11 and the pressure adjusting valve 12, if both arecontrolled only by the signal of vent box 8, the movement of valvesinterferes with each other and therefore the pressure retention becomesunstable. Therefore, it is desirable that the decompression valve 11 iscontrolled using a signal of the pressure difference between forward andback thereof and the pressure adjusting valve 12 is controlled using asignal of the pressure of vent box 8 itself.

With these mechanisms, the inner pressure of vent box 8 can be alwayskept nearly constant, and the continuous and uniform extrusion moldingcan be conducted by the molding means of degassing extruder 2.

For the safety operation, the vent box may have a relief valve 8 a forthe unexpected instability of the pressure of the vent box.

For example, in these apparatuses, the continuous stable operation ofmore than 5 hours can be performed in the range of 2 to 100 kg/h perunit time as the processing amount of cross-linked polyethylene that canbe permitted by the discharge capacity of extruder.

FIG. 2 is a flow diagram showing a cross-link cutting treatmentapparatus for cross-linked polyethylene in the other preferredembodiment of the invention.

In this embodiment, the vent 9 is attached to the degassing extruder 2as explained with reference to FIG. 1. Thereby, the remaining reactionagent in the polymer treatment product escapes from the vent 9 through avalve 91 to the combustor 20 side. Therefore, the reaction agent can bemore perfectly removed from the polymer treatment product.

By using this apparatus, as with the previous embodiment in FIG. 1, thecontinuous stable operation of more than 5 hours can be performed in therange of 2 to 100 kg/h per unit time as the processing amount ofcross-linked polyethylene that can be permitted by the dischargecapacity of extruder.

FIG. 4 is a flow diagram showing a cross-link cutting treatmentapparatus for cross-linked polyethylene as comparative example 1.

In operation, as with the apparatus shown in FIG. 1, thermosetting resinor cross-linked polymer being pelletized is put through the hopper 13 inthe polymer material supplying extruder 1. The polymer materialsupplying extruder 1 has the same as that shown in FIG. 1. On the otherhand, ethanol as a cross-link decomposition reaction agent is suppliedfrom the reaction agent tank 18 through the valve 17, the reaction agentsupplying pump 15 and the reaction agent heater 14 to the polymermaterial supplying extruder 1.

In the polymer material supplying extruder 1, the thermosetting resin orcross-linked polymer, which is retained at high-temperature andpressure, reacts with ethanol in supercritical state and is plasticized.The mixture of plasticized polymer treatment product and reaction agentis, after the sufficient reaction conducted in the distribution typereaction vessel 100, stepwise depressurized by the decompression valve11, and then by the breaker plate 31, which is a resistor body withmultiple holes for decompression of the resin, attached to thedecompression valve 11. Then, different from the embodiment in FIG. 1,the mixture is sent to a reaction agent separation tank 208 that is at apressure slightly higher than atmospheric pressure and lower than thatof the distribution type reaction vessel 100.

In the reaction agent separation tank 208, a viscous liquid polymertreatment product 209 is separated from the gaseous reaction agent. Thereaction agent separation tank 208 is heated by a heater 210 as anelectric heater to be kept at a temperature that the polymer treatmentproduct 209 is in fluid state. The inner pressure of the reaction agentseparation tank 208 is kept higher than atmospheric pressure and therebythe polymer treatment product 209 can be easily discharged outside thereaction agent separation tank 208. The polymer treatment product isthen sent to the degassing extruder 2 and molded by the die 3 at thedischarge end of degassing extruder 2. The degassing extruder 2 may be asingle-shaft or double-shaft extruder. In this example, the polymertreatment product is molded into the filamented strand 5 and is thencooled and hardened nearly at room temperature by the cooler 4. Thestrand 5 is cut into pellets 7 by the strand cutter 6. The degassingextruder 2 may be, as shown in FIG. 2, equipped with the vent 9 so as toperfectly remove the reaction agent from the resin.

On the other hand, the reaction agent, ethanol separated from thepolymer treatment product 209 in the reaction agent separation tank 208is depressurized to atmospheric pressure through a tank pressureadjusting valve 212, and then transferred to the impurity separationtank 16. In the impurity separation tank 16, impurities generated in thereaction process and mixed in the reaction agent, ethanol are separatedusing a difference of boiling points. Ethanol is returned to thereaction agent tank 18, and the impurities are drawn through a blower 19into a combustor 20, where they are burned.

In using the apparatus of comparative example 1, when the resin isintermittently discharged, the resin discharged sticks to the wall ofthe reaction agent separation tank 208 and therefore, the supply ofresin to the degassing extruder 2 discontinues. Thus, in comparativeexample 1, the continuous operation cannot be stably performed for longhours.

Comparative example 2 is provided such that the vent box 8 as vent backin FIG. 1 has a volume of half that of the distribution type reactionvessel 100.

In using the apparatus of comparative example 2, when the resin isintermittently discharged, the inner pressure of vent box 8 becomeshigher than half of that of the distribution type reaction vessel 100,due to the discharged resin and alcohol. Thus, the vent box 8 may bebroken. Further, when the operation continues, the resin being blown outfrom the vent box 8 sticks to the vacuuming piping system and thedegassing from the piping system discontinues. Therefore, the operationis stopped.

Although the invention has been described with respect to the specificembodiments for complete and clear disclosure, the appended claims arenot to be thus limited but are to be construed as embodying allmodifications and alternative constructions that may occur to oneskilled in the art which fairly fall within the basic teaching hereinset forth.

1. A polymer treating apparatus for reacting a polymer compound with areaction agent in a reaction vessel to generate a polymer treatmentproduct, comprising: a decompression device configured to decompress thepolymer treatment product which has been discharged from the reactionvessel, wherein the polymer treatment product contains the reactionagent; a degassing extruder configured to receive the polymer treatmentproduct discharged from the decompression device and configured toextrude the polymer treatment product; and a vent box that is connectedto upstream of the degassing extruder and that has a volume of equal toor more than that of the reaction vessel, wherein the vent box isconfigured to separate the reaction agent from the polymer treatmentproduct.
 2. The polymer treating apparatus according to claim 1, furthercomprising: an impurity separation device that is connected to the ventbox and configured to separate an impurity from the separated reactionagent; and a pressure adjusting device that is disposed between the ventbox and the impurity separation device, wherein the pressure adjustingdevice is configured to keep constant the inner pressure of the ventbox, wherein the vent box comprises a heating device that is disposed onthe periphery of the vent box so as to heat the vent box.
 3. The polymertreating apparatus according to claim 1, wherein: the vent box comprisesa relief valve configured to prevent over pressurization of the ventbox.
 4. The polymer treating apparatus according to claim 2, wherein:the heating device comprises an electric heater that is disposed on aperiphery of a storing portion for the polymer treatment product of thevent box.
 5. The polymer treating apparatus according to claim 2,wherein: the heating device comprises a jacket for circulation ofheating medium that is disposed on the periphery of a storing portionfor the polymer treatment product of the vent box, and a heating mediumcirculation unit that supplies the heating medium to the jacket.
 6. Thepolymer treating apparatus according to claim 2, wherein: the impurityseparation device comprises a storing tank that stores the separatedreaction agent, wherein the impurity separation device is configured tosupply the stored reaction agent to the reaction vessel with the polymercompound.
 7. The polymer treating apparatus according to claim 2,wherein: the impurity separation device comprises a filter that canseparate the reaction agent from the polymer treatment product from thedegassing extruder.
 8. The polymer treating apparatus according to claim1, further comprising: a cooling device that cools the polymer treatmentproduct extruded from the degassing extruder; and a cutting device thatcuts the cooled polymer treatment product.
 9. The polymer treatingapparatus according to claim 1, wherein: the decompression devicecomprises a discharge valve.
 10. The polymer treating apparatusaccording to claim 1, wherein: the decompression device comprises aresistor body with multiple holes.
 11. The polymer treating apparatusaccording to claim 1, wherein: the decompression device comprises aresistor body with multiple holes and/or a flow rate adjusting valve.12. The polymer treating apparatus according to claim 1, wherein thedegassing extruder comprises a double-shaft extruder.
 13. The polymertreating apparatus according to claim 1, wherein the degassing extrudercomprises a vent disposed on a discharge side thereof configured toremove the reaction agent remaining in the polymer treatment product.14. The polymer treating apparatus according to claim 1, wherein thereaction vessel is a distribution type reaction vessel that is connectedto a polymer material supplying extruder at a previous stage.
 15. Thepolymer treating apparatus according to claim 1, wherein the degassingextruder is configured to mold the polymer treatment product whileextruding the polymer treatment product.
 16. The polymer treatingapparatus according to claim 1, wherein the reaction vessel isconfigured to react polymer compound that is pelletized.
 17. The polymertreating apparatus according to claim 1, wherein the reaction vessel isconfigured to react polymer compound that has a cross-linked structureor a molecular three-dimensional network structure.